The purpose of this proposal is to build a mentored, clinical research training experience to foster independent professional development in cancer control research. This application is being submitted from the University of Pennsylvania Cancer Center, which provides a setting with excellent opportunities to work with Dr. Caryn Lerman, the Transdisciplinary Tobacco Use Research Center (TTURC), and my co-sponsors, Drs. Charles O'Brien and J. Sanford Schwartz. Sound career development in cancer control research requires broad exposure to research methodologies and intensive research training in order to make significant, independent contributions to this field. Therefore, this K07 Career Development Award application seeks to achieve these goals in the area of tobacco control and maternal and child health. General plans for the career development program include: (a) expanding working knowledge of areas relevant to cancer/tobacco control research; (b) refining skills in the application of behavioral science to cancer/tobacco control; (c) increasing knowledge of maternal health issues related to cancer/tobacco control; (d) expanding understanding of the biobehavioral mechanisms of tobacco addiction; (e) improving skills in designing, implementing, and analyzing cancer/tobacco control interventions; and (f) learning effective ways to disseminate research findings to impact upon public health practices. Specifically, the research project aims to develop a low-cost, primary-care intervention to reduce children's Environ- mental Tobacco Smoke exposure and maternal smoking rates targeting under- served mothers with children ages 0-2. The effectiveness of this intervention will be tested by comparing it with a standard care control-group intervention using a two-group, repeated measures randomized design. The intervention will be modeled after more intensive, home-based counseling programs, the feasibility of which has been demonstrated. However, as these interventions were labor intensive and costly, the proposed intervention presents an innovative, comprehensive, albeit streamlined primary-care approach to an emerging issue in the tobacco control field. This intervention will also set the groundwork for an eventual R01 that will test the treatment and prevention efficacy of this intervention on other populations (e.g., adolescent smokers and their younger, nonsmoking siblings).